Publications by authors named "David K Donald"

Article Synopsis
  • A series of muscarinic receptor antagonists were created to find an effective treatment for COPD, focusing on compounds with strong M3 receptor effects and fewer side effects.
  • Modifications to initial compounds led to a specific cycloheptyl and quinuclidine sub-series, which were tested with various N-substituents to find the best combination for potency and safety.
  • Following in vitro evaluations, the top-performing compounds were tested in guinea pigs for their effectiveness and side effects, resulting in AZD8683 being chosen for clinical trials due to its promising long-lasting effects and therapeutic profile.
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We have recently described the immunosuppressive properties of AR-C117977 and AR-C122982, representatives of a group of compounds identified as inhibitors of lactate transporters (monocarboxylate transporters; MCTs). These compounds demonstrate the potential therapeutic usefulness of inhibiting MCT-1, but their physical and metabolic properties made them unsuitable for further development. We have therefore tried to find analogues with similar immunosuppressive efficacy and a more suitable profile for oral administration.

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The optimization of a new series of muscarinic M(3) antagonists is described, leading to the identification of AZD9164 which was progressed into the clinic for evaluation of its potential as a treatment for COPD.

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Background: In a search for immunosuppressive drugs having novel mechanisms, monocarboxylate transporter (MCT-1) inhibitors were identified that markedly inhibited immune responses. Here, we report the effects of AR-C117977, a potent MCT-1 inhibitor, on alloimmune responses in the rat.

Methods: In vitro activity was determined in a rat mixed lymphocyte response (MLR).

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A novel series of antagonists of the human P2X7 receptor is described. Modification of substituents enabled identification of compounds selective for the rat P2X7 receptor and provides useful pharmacological tools for evaluation of the role of P2X7 in disease.

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We have previously described a novel series of potent blockers of the monocarboxylate transporter, MCT1, which show potent immunomodulatory activity in an assay measuring inhibition of PMA/ionomycin-induced human PBMC proliferation. However, the preferred compounds had the undesirable property of existing as a mixture of slowly interconverting rotational isomers. Here we show that variable temperature NMR is an effective method of monitoring how alteration to the nature of the amide substituent can modulate the rate of isomer exchange.

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Current immunosuppressive therapies act on T lymphocytes by modulation of cytokine production, modulation of signaling pathways or by inhibition of the enzymes of nucleotide biosynthesis. We have identified a previously unknown series of immunomodulatory compounds that potently inhibit human and rat T lymphocyte proliferation in vitro and in vivo in immune-mediated animal models of disease, acting by a novel mechanism. Here we identify the target of these compounds, the monocarboxylate transporter MCT1 (SLC16A1), using a strategy of photoaffinity labeling and proteomic characterization.

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